Products that can make the parallel outputs 'H' at the same time are the CMOS output type BU2152 and open drain output (requiring pull-up) types BU2099 and BU2092. The BU2152 sets the CLB pin to 'L' while the BU2099 and BU2092 sets the OE pin to 'H', with the outputs becoming 'H' asynchronously with other signals.Related Link：Technical Document
Products that can make the parallel output 'L' simultaneously are the CMOS output type BU2050 and open drain output type BU2098. Setting the /CLR pin to 'L' will allow the BU2050 to set all outputs to 'L' asynchronously with other input signals. And for the BU2098, all outputs become 'L' by power ON reset only when the power is turned ON.Related Link：Technical Document
The BU2092 and BU2099 do not have a power ON reset function, so the initial values of the internal shift register will be random. Setting /OE='H' makes it possible to turn all open collector outputs OFF (all outputs High if there is a pull-up resistor), regardless of other inputs. All outputs ON (Low) is not possible. If the internal shift register is not set to that state in advance, initial random values will be output when /OE='L'.
The maximum current of 25mA indicated in the datasheet is the maximum current that can flow to one output pin. The total current value must be within the total output current specification or the range not exceeding the total permissible loss.
Since there is no diode with respect to the power supply at the open drain pin, even if a voltage higher than the power supply is supplied to the output, there will be no flow from the output to the power supply. However, please be careful not to exceed the recommended operating conditions and permissible loss.